Experience Is the Best Teacher
Why is it that our kids always want to do things that are dangerous? Like, why do they want to learn how to skateboard when they can just sit at home all day in front of the computer? Why is it that our toddlers have some weird attraction to the pedestal fan and always want to stick their fingers in the spinning blade?
This person stopped their three-year-old from getting their fingers chopped up in the fan. But after the second time, they figured that their child had to know what happened when you did it. After letting nature take its course, hopefully, the child never repeated it ever again.